Submission #1160032

#	TimeUTC-0	Username	Problem	Language	Result	Execution time	Memory
1160032	2025-03-01 16:26:19	Hamed_Ghaffari	Railway (BOI17_railway)	C++20	0 / 100	38 ms	23996 KiB

railway

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#include<bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
#define pb push_back
#define all(x) x.begin(), x.end()
const int MXN = 1e5+5;
const int LOG = 17;
int n, par[LOG][MXN], stt[MXN], fnt[MXN], timer;
vector<pii> g[MXN];
void dfs(int v) {
    for(int i=1; i<LOG; i++)
        par[i][v] = par[i-1][par[i-1][v]];
    stt[v] = timer++;
    for(auto [u, i] : g[v])
        if(u!=par[0][v])
            par[0][u]=v,
            dfs(u);
    fnt[v] = timer;
}
bool is_anc(int u, int v) { return stt[u]<=stt[v] && fnt[v]<=fnt[u]; };
int LCA(int u, int v) {
    if(is_anc(u, v)) return u;
    for(int i=LOG-1; i>=0; i--)
        if(par[i][u] && !is_anc(par[i][u], v))
            u = par[i][u];
 
 
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• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25